They've been where no man has gone before. Join http://www.WatchMojo.com as we count down our picks for the top 10 most well-documented UFO sightings.
UFO, unidentified flying object, aliens, flying saucer, hoax, conspiracy, Roswell, Mount Rainier, Mantell UFO incident, NASA, Phoenix Lights, Kenneth Arnold, Washington D.C. Flap, Tether Incident, Kecksburg, Belgian UFO Wave, Baltic Sea anomaly